1. UPC Assignment 1 Sample problems

2. Consider the following UPC-A code. Is it a valid UPC? 0 11110 86852-7

3. Consider the following UPC-A code. Is it a valid UPC? 0 11110 86852-7 The answer is Yes

4. How can we get ? 1.odd-digit sum: 0+1+1+8+8+2=20 2.even-digit sum: 1+1+0+6+5=13 3.odd*3+even = 20*3+13=73 4.mod 10: 73 mod 10 = 3 5.subtract from 10=10-3=7

5. Consider the following UPC-A code. What is the missing digit (shown as a question mark)? 0 21130 27566-?

6. The answer is 3

7. How can we get ? 1.odd-digit sum: 0+1+3+2+5+6=17 2.even-digit sum: 2+1+0+7+6=16 3.odd*3+even = 17*3+16=67 4.mod 10: 67 mod 10 = 7 5.subtract from10=10-7=3

8. Consider the following UPC-A code. What is the missing digit (shown as a question mark)? 0 70?30 50606 0

9. The answer is 3

10. How can we get ? 1.odd-digit sum: 0+0+3+5+6+6=20 2.even-digit sum: 7+x+0+0+0=7+x 3.odd*3+even = 20*3+7+x=67+x 4.mod 10: (67+x)mod 10 5.checking number is 0, so (67+x)mod10=0 =>x=3

11. Consider the following UPC-A code. What is the missing digit (shown as a question mark)? 0 787?7 50758 6

12. The answer is 8

13. How can we get ? 1.odd-digit sum: 0+8+x+5+7+8=28+x 2.even-digit sum: 7+7+7+0+5=26 3.odd*3+even = (28+x)*3+26=110+3x 4.subtract from 10: 10-(110+3x)mod10=6 =>(110+3x)mod10=4 =>x=8